Colorectal cancer is an important cancer worldwide, and its incidence is increasing year by year. A large proportion of patients may require diverting stoma or even permanent stoma after surgery. Some of these patients will have a variety of stoma-related complications, which seriously affect the quality of life of patients. At present, the mainstream postoperative complication classification is the traditional CD classification, which is suitable for the classification of most postoperative complications. However, due to the unique anatomical characteristics of patients with stoma, the current CD classification system may not be suitable for the classification of patients with stoma-related complications. Therefore, we plan to establish a registry database of colorectal cancer patients with stoma, explore the attribution and incidence of stoma-related complications, and propose a new improved classification system, the SITI classification, on the existing CD classification, for verification and promotion.

The complications related to stoma can be divided into five categories: skin complications near stoma (SKIN), abdominal incision complications at stoma (INCISION), abdominal wall fascia tunnel complications (abdominal Fascia/Muscular Tunnel complications), intestinal and mesenteric complications（Intestine）, and functional complications of ileostomy (Dehydration after IL). According to the actual situation of colostomy patients, the SITI classification is proposed to classify the complications from Grade Ia to V. The specific classification is as follows: Grade Ia, only need to observe, no treatment. Grade Ib, non-invasive treatment is required, and no drug is used. Grade IIa, invasive treatment without anesthesia, such as filling or local medication. Grade IIb, except for Grade IIa treatment, drugs, antibiotics, blood transfusion, etc. are used throughout the body. Grage IIIa, requiring intervention under local anesthesia. Grade IIIb, requiring intervention treatment of general anesthesia. Grade IVa, life threatening complications, including dialysis and single organ dysfunction. Grade IVb, complication of multiple organ dysfunction. Grade V, patient died. Classification, classification and grading can help ostomy therapists effectively identify and manage ostomy complications. The establishment of the database is convenient for researchers to explore the attribution of complications and the incidence of various types of complications.

Inclusion Criteria:

• Patients with stoma after colorectal cancer resection.

Exclusion Criteria:

• Patients who don't want to be studied

Patients with colostomy after bowel cancer surgery were followed up for one year to understand the type and occurrence time of the complications of colostomy. Patients who were unwilling to accept the study were excluded

Based on SITI classification, we will decide whether to conduct multicenter study or not